oSIST prEN 1366-8:2023
(Main)Fire resistance tests for service installations - Part 8: Smoke extraction ducts
Fire resistance tests for service installations - Part 8: Smoke extraction ducts
This document specifies a test method for determining the fire resistance of smoke extraction ducts. It is applicable only to smoke extraction ducts that pass through another fire compartment from the fire compartment to be extracted in case of fire. It represents fire exposure of a fully developed fire.
This method of test is only applicable to fire resistant ventilation ducts (same construction) with the following classification according to EN 13501-3:
- fire from inside and outside i ↔ o;
- applicable to a pressure difference up to 500 Pa;
NOTE 1 It is assumed that the duct A test(s) in accordance with EN 1366-1 has been performed with an under-pressure of minimum 500 Pa.
- with integrity (E) and insulation (I) criteria equal to or higher than the intended classification for the smoke extraction duct.
For the purposes of the test described in this document, the duct is referred to as duct C.
This test method has been designed to cover both vertical and horizontal smoke extraction ducts. A vertical system need not be evaluated to this method provided that:
- both horizontal (ho) and vertical (ve) classification according to EN 13501-3 has been obtained for the ventilation duct, and
- it has been tested in a horizontal orientation to this method.
If the ventilation duct in practice is only used for vertical applications in smoke extraction systems, only vertical (ve) classification is bound to be used and tested in a vertical orientation to this method according to EN 13501-3.
This test method is suitable for ducts constructed from non-combustible materials (Euroclass A1 and A2 according to EN 13501-1).
NOTE 2 Reaction with components of the duct can reduce the oxygen concentration and lead to misinterpretation of the calculated leakage rate.
This standard applies to four sided ducts only (with fire exposure on all four sides). Ducts that utilize elements of construction for one, two or three sides are not covered. An alternative test method for one, two and three sided ducts will be developed separately.
Feuerwiderstandsprüfungen für Installationen - Teil 8: Entrauchungsleitungen
Dieses Dokument legt ein Prüfverfahren zur Bestimmung der Feuerwiderstandsfähigkeit von Entrauchungsleitungen fest. Dieses Prüfverfahren gilt nur für Entrauchungsleitungen, die von einem Brandabschnitt, aus dem der Rauch im Brandfall abgesaugt werden soll, über einen weiteren Brandabschnitt führen. Es stellt die Brandeinwirkung für einen Vollbrand dar.
Dieses Prüfverfahren ist nur für feuerwiderstandsfähige Lüftungsleitungen (gleiche Bauweise) mit der folgenden Klassifizierung nach EN 13501 3 anwendbar:
- Feuer von innen und außen i ↔ o;
- anwendbar bis zu einer Druckdifferenz von bis zu 500 Pa;
ANMERKUNG 1 Es wird angenommen, dass die Prüfung(en) von Leitung A nach EN 1366 1 mit einem Unterdruck von mindestens 500 Pa durchgeführt wurde(n).
- mit den Kriterien Raumabschluss (E) und Wärmedämmung (I) gleich oder höher als die geplante Klassifizierung für die Entrauchungsleitung.
Für die in diesem Dokument beschriebene Prüfung wird die Leitung als Leitung C bezeichnet.
Dieses Prüfverfahren ist sowohl für vertikale als auch horizontale Entrauchungsleitungen vorgesehen. Ein vertikales System muss nicht nach diesem Verfahren geprüft werden, wenn
- sowohl die horizontale (ho) als auch die vertikale (ve) Klassifizierung nach EN 13501 3 für die Lüftungsleitung ermittelt wurde, und
- es nach diesem Verfahren in horizontaler Anordnung geprüft wurde.
Wenn die Lüftungsleitung jedoch in der Praxis nur für vertikale Anwendungen innerhalb eines Rauchabzugssystems verwendet wird, muss nur die vertikale (ve) Klassifizierung verwendet werden und nach diesem Verfahren in vertikaler Anordnung nach EN 13501 3 geprüft werden.
Das Prüfverfahren ist nur für Leitungen aus nichtbrennbaren Baustoffen geeignet (Euroklassen A1 und A2 nach EN 13501 1).
ANMERKUNG 2 Die Reaktion mit Komponenten der Leitung kann die Sauerstoffkonzentration reduzieren und zu Fehlinterpretationen der berechneten Leckagerate führen.
Diese Norm ist nur für vierseitige Kanäle anwendbar (mit Brandeinwirkung auf allen vier Seiten). Leitungen, die Bauelemente für eine, zwei oder drei Seiten verwenden, werden nicht behandelt. Ein alternatives Prüfverfahren für ein-, zwei- und dreiseitige Leitungen wird separat entwickelt.
Essais de résistance au feu des installations techniques - Partie 8: Conduits d'extraction de fumées
Le présent document définit une méthode d’essai de détermination de la résistance au feu des conduits d’extraction de fumées et s’applique uniquement aux conduits d’extraction de fumée qui traversent un compartiment différent du compartiment feu dont les fumées sont à extraire en cas d’incendie. Il décrit les conditions d’exposition à un feu pleinement développé.
Cette méthode d’essai est uniquement applicable aux conduits de ventilation résistant au feu (construits de la même façon) ayant le classement suivant conformément à l’EN 13501-3 :
- feu provenant de l’intérieur ou de l’extérieur, i ↔ o ;
- applicable à un différentiel de pression allant jusqu’à 500 Pa ;
NOTE 1 Par hypothèse, le ou les essais sur les conduits A ont été réalisés avec une dépression d’au moins 500 Pa, conformément à l’EN 1366-1.
- ayant des critères d’étanchéité au feu (E) et d’isolation (I) supérieurs ou égaux au classement prévu pour le conduit d’extraction de fumées.
Pour les besoins des essais décrits dans le présent document, le conduit concerné est appelé conduit C.
Cette méthode d’essai a été conçue pour couvrir aussi bien les conduits d’extraction de fumées verticaux qu’horizontaux. Il n’est pas nécessaire d’évaluer un système vertical selon cette méthode si :
- les classements aussi bien horizontal (ho) que vertical (ve) conformément à l’EN 13501-3 ont été obtenus pour le conduit de ventilation ; et
- les essais horizontaux ont été effectués suivant cette méthode.
Si, dans la pratique, le conduit de ventilation n’est utilisé que pour des applications verticales dans des systèmes d’extraction de fumées, il n’est obligatoire d’utiliser que le classement vertical (ve) et de soumettre le conduit à essai dans une orientation verticale selon cette méthode conformément à l’EN 13501-3.
Cette méthode d’essai est valable pour des conduits fabriqués à partir de matériaux non combustibles (Euroclasse A1 et A2 conformément à l’EN 13501-1).
NOTE 2 Des réactions avec les composants du conduit peuvent réduire la concentration d’oxygène et entraîner une interprétation erronée du débit de fuite calculé.
La présente norme s’applique uniquement aux conduits à quatre côtés (avec exposition au feu sur les quatre côtés). Les conduits constitués d’éléments de construction pour un, deux ou trois côtés ne sont pas couverts. Une méthode d’essai différente pour les conduits à un, deux et trois côtés sera développée spécifiquement.
Preskusi požarne odpornosti servisnih inštalacij – 8. del: Kanali za odvod dima
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN 1366-8:2023
01-julij-2023
Preskusi požarne odpornosti servisnih inštalacij – 8. del: Kanali za odvod dima
Fire resistance tests for service installations - Part 8: Smoke extraction ducts
Feuerwiderstandsprüfungen für Installationen - Teil 8: Entrauchungsleitungen
Essais de résistance au feu des installations techniques - Partie 8: Conduits d'extraction
de fumées
Ta slovenski standard je istoveten z: prEN 1366-8
ICS:
13.220.50 Požarna odpornost Fire-resistance of building
gradbenih materialov in materials and elements
elementov
91.060.40 Dimniki, jaški, kanali Chimneys, shafts, ducts
oSIST prEN 1366-8:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 1366-8:2023
DRAFT
EUROPEAN STANDARD
prEN 1366-8
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2023
ICS 13.220.50 Will supersede EN 1366-8:2004
English Version
Fire resistance tests for service installations - Part 8:
Smoke extraction ducts
Essai de résistance au feu des installations de service - Feuerwiderstandsprüfungen für Installationen - Teil 8:
Partie 8: Conduits d'extraction de fumées Entrauchungsleitungen
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 127.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1366-8:2023 E
worldwide for CEN national Members.
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prEN 1366-8:2023 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Test equipment . 7
5 Test conditions . 9
6 Test specimen . 10
7 Installation of test specimen . 12
8 Conditioning . 13
9 Application of instrumentation . 13
10 Test procedure . 15
11 Performance criteria . 18
12 Test report . 20
13 Field of direct application of test results . 21
Annex A (normative) Measurement of volume/mass flow . 38
A.1 Hints on measuring volume flow or mass flow with differential pressure devices . 38
A.2 Density . 38
A.3 Absolute Pressure (barometric pressure) . 39
A.4 Viscosity . 39
A.5 Characteristic data of the inlet nozzles according to Figure 7 of this standard . 40
Annex B (informative) Measurement of oxygen concentration Details on measuring oxygen
concentration with paramagnetic cell analysers . 43
B.1 General. 43
B.2 Choice of O measuring devices . 43
2
B.3 Effect of O measuring device errors . 44
2
B.4 Zero and end point drift . 44
Annex C (informative) The usage of correction factors for the consideration of different
parameters . 46
C.1 Details for the development of the correction factors and their error limits . 46
C.2 The complete formula for the leakage mass flow and the parameters . 46
C.3 Application of correction factors in the simple mass flow formulae and achievable
accuracy . 49
Bibliography . 50
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European foreword
This document (prEN 1366-8:2023) has been prepared by Technical Committee CEN/TC 127 “Fire safety
in buildings”, the secretariat of which is held by BSI.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 1366-8:2004.
In comparison with the previous edition, the following technical modifications have been made:
— method for determination of reduction in internal cross-section area is added;
— positions for measurement of deflection of cross-section outside furnace are defined;
— introduction of an alternative oxygen sampling probe;
— use of two separate O analysers based on paramagnetic measurement method for the two sampling
2
points is mandatory;
— failure criteria for mechanical stability of duct inside furnace defined.
This document has been prepared under a Standardization Request given to CEN by the European
Commission and the European Free Trade Association.
EN 1366, Fire resistance tests for service installations consists of the following parts:
— Part 1: Ventilation ducts;
— Part 2: Fire dampers;
— Part 3: Penetration seals;
— Part 4: Linear joint seals;
— Part 5: Service ducts and shafts;
— Part 6: Raised access and hollow core floors;
— Part 7: Conveyor systems and their closures;
— Part 8: Smoke extraction ducts;
— Part 9: Single compartment smoke extraction ducts;
— Part 10: Smoke control dampers;
— Part 11: Fire protective Systems for cable systems and associated components;
— Part 12: Non-mechanical fire barrier for ventilation ductwork;
— Part 13: Chimneys.
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Introduction
This document has been prepared because a method of test for fire resisting smoke extraction ducts has
become necessary to evaluate the ability of fire resisting ducts already tested to EN 1366-1 to function
adequately as smoke extraction ducts.
Leakage is measured at both ambient and elevated temperatures. During the tests, air/gases are drawn
through the duct at a differential pressure between the inside and outside of the duct. Leakage is
determined at ambient temperature by sealing the openings in the duct located in the furnace and taking
flow measurements through a flow-measuring device located just before the extraction fan. With respect
to determining leakage at elevated temperatures, oxygen concentration measuring techniques are used.
The method described in this test is complex and requires sophisticated instrumentation. It is not
recommended therefore to try to test multiple assemblies in this test.
The attention of all persons concerned with managing and carrying out this fire resistance test is drawn
to the fact that fire testing can be hazardous and that there is a possibility that toxic and/or harmful
smoke and gases might be evolved during the test. Mechanical and operational hazards might also arise
during the construction of the test elements or structures, their testing and disposal of test residues.
An assessment of all potential hazards and risks to health should be made and safety precautions should
be identified and provided. Written safety instructions should be issued. Appropriate training should be
given to relevant personnel. Laboratory personnel should ensure that they follow written safety
instructions at all times.
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1 Scope
This document specifies a test method for determining the fire resistance of smoke extraction ducts. It is
applicable only to smoke extraction ducts that pass through another fire compartment from the fire
compartment to be extracted in case of fire. It represents fire exposure of a fully developed fire.
This method of test is only applicable to fire resistant ventilation ducts (same construction) with the
following classification according to EN 13501-3:
— fire from inside and outside i ↔ o;
— applicable to a pressure difference up to 500 Pa;
NOTE 1 It is assumed that the duct A test(s) in accordance with EN 1366-1 has been performed with an
under-pressure of minimum 500 Pa.
— with integrity (E) and insulation (I) criteria equal to or higher than the intended classification for the
smoke extraction duct.
For the purposes of the test described in this document, the duct is referred to as duct C.
This test method has been designed to cover both vertical and horizontal smoke extraction ducts. A
vertical system need not be evaluated to this method provided that:
— both horizontal (ho) and vertical (ve) classification according to EN 13501-3 has been obtained for
the ventilation duct, and
— it has been tested in a horizontal orientation to this method.
If the ventilation duct in practice is only used for vertical applications in smoke extraction systems, only
vertical (ve) classification is bound to be used and tested in a vertical orientation to this method according
to EN 13501-3.
This test method is suitable for ducts constructed from non-combustible materials (Euroclass A1 and A2
according to EN 13501-1).
NOTE 2 Reaction with components of the duct can reduce the oxygen concentration and lead to
misinterpretation of the calculated leakage rate.
This standard applies to four sided ducts only (with fire exposure on all four sides). Ducts that utilize
elements of construction for one, two or three sides are not covered. An alternative test method for one,
two and three sided ducts will be developed separately.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 1363-1, Fire resistance tests - Part 1: General requirements
EN 1366-1, Fire resistance tests for service installations - Part 1: Ventilation ducts
EN 1507, Ventilation for buildings - Sheet metal air ducts with rectangular section - Requirements for
strength and leakage
EN 10095, Heat resisting steels and nickel alloys
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EN 13501-3, Fire classification of construction products and building elements - Part 3: Classification using
data from fire resistance tests on products and elements used in building service installations: fire resisting
ducts and fire dampers
EN 13501-4, Fire classification of construction products and building elements - Part 4: Classification using
data from fire resistance tests on components of smoke control systems
EN 60584-1, Thermocouples - Part 1: EMF specifications and tolerances (IEC 60584-1)
EN ISO 13943, Fire safety - Vocabulary (ISO 13943)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1363-1 and EN ISO 13943 and
the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
smoke extraction duct
fire resistant duct used for the extraction of smoke in case of fire
3.2
fire-resistant ventilation duct
duct used for the distribution or extraction of air and designed to provide a degree of fire resistance
[SOURCE: EN 1366-1:2014+A1:2020, definition 3.1]
3.3
self-supporting duct
duct constructed from fire-protective boards, without encasing a steel duct
[SOURCE: EN 1366-1:2014+A1:2020, definition 3.3]
3.4
suspension devices
components used for securing a duct to a load bearing structure
3.5
supporting construction
wall, partition or floor through which the duct passes in the test
[SOURCE: EN 1366-1:2014+A1:2020, definition 3.5]
3.6
compensator
device used to prevent damage to the duct, the penetration seal and/or the structural elements
(horizontal or vertical) from the forces that are generated by the thermal expansion of the duct and/or
its suspension devices
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3.7
access panel
cover for an inspection opening within the duct
[SOURCE: EN 1366-1:2014+A1:2020, definition 3.7]
3.8
fire protected steel duct
steel duct with an external insulation to provide fire resistance
[SOURCE: EN 1366-1:2014+A1:2020, definition 3.8]
3.9
internal surface area with under-pressure
surface area of the duct from the perforated plate to the end of the duct by the inlet nozzles including the
endplate where the nozzles are positioned and excluding the surface of the perforated plate
3.10
total internal surface area
full internal area of the duct including both end plates
4 Test equipment
4.1 General
In addition to the test equipment specified in EN 1363-1, the following is required:
4.2 Furnace
This shall be capable of subjecting smoke extraction ducts to the standard heating and pressure
conditions specified in EN 1363-1 and be suitable for testing ducts in the horizontal (see Figure 1) or
vertical (see Figure 2) orientation.
It is required that the construction of furnace shall allow observation of at least 75 % of the test specimen.
4.3 Perforated plate
The perforated plate defines the under-pressure inside the duct by the air flow speed of 2 m/s in ambient
conditions. Choose the perforated plate from Figure 3 or Figure 4 to suit the required pressure level
according to Table 1. The plate shall be positioned (250 ± 50) mm from where the duct passes through
the furnace wall or roof, see Figures 1 and 2.
The plate shall be made from austenitic heat-resisting steel (grade number 1.4835 or 1.4828) in
accordance with EN 10095 Heat resisting steels and nickel alloys. The number of holes and dimensions
are given in Figures 3 and 4. The thickness of the plates shall be 2,5 ± 0,5 mm.
NOTE 1 The table in Figure 3 gives details of perforated plates for standard rectangular ducts of size 1 000 mm
x 250 mm. For smaller sizes, the number of holes will be reduced proportional to the smaller cross section.
NOTE 2 The table in Figure 4 gives details of perforated plates for standard circular ducts of diameter 560 mm.
For smaller sizes, the number of holes will be reduced proportional to the cross section (a change to larger sizes is
not permitted; see 6.1.3 and Table 3).
Further details of the plate are shown in Figures 3, 4 and 5.
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Table 1 — Differential pressures between inside and outside the duct for smoke extraction
ductwork
Differential pressure for fire
Operating differential pressure
at ambient temperature
Pressure level test and pre-test calibration
Pa
Pa
1 −500 −150
2 −1 000 −300
3 −1 500 −500
4.4 Inlet nozzles
The measuring device shall be capable of measuring to an accuracy of + 5 % when used in cold conditions
and shall be suitably mounted to the end of the duct with its piezometric ring connected to appropriate
differential pressure measuring equipment
NOTE 1 For the standard sizes of ducts specified in 7.1, an internal dimension of diameter = 160 mm of each
nozzle is suitable (cf. Figure 7). Descriptions of similar nozzles are given in EN ISO 5167-3, EN ISO 5167-4 and
ISO 5221.
NOTE 2 Suggestion to an inlet nozzles system for standard size ducts is shown in Figures 6 and 7. The calculation
procedure is given in Annex A.
4.5 Ambient temperature leakage measuring device
The measuring device shall be capable of measuring to an accuracy of ±2,5 % and suitably mounted at
the end of the duct, connected to appropriate differential pressure measuring equipment.
NOTE Descriptions of possible measuring devices are given in the EN ISO 5167 series and ISO 5221.
4.6 Pressure sensors for differential pressure control
A tube sensor as specified in EN 1363-1 shall be located at the end of the duct, inside the duct, at the level
of its centre line. As an alternative to this tube sensor, a piezometric ring can be used. An example for the
piezometric ring is shown in Figure 7, item 4.
A second sensor (e.g. an open end of a measuring tube) shall be located on the same level outside the
duct. This is shown in Figures 6 and 7 as pressure sensor D1.
4.7 Welded connecting duct
A duct tightly welded, which is designed to provide a suitable gas tight connection between the inlet
nozzles and the oxygen measuring probes, shall be provided.
One end of the duct is designed to connect between the test specimen and the extraction fan. An inlet
opening may be provided if a flow control damper is used for fine control of the differential pressure. This
is shown in Figure 7, item 7.
4.8 Extraction fan
A fan for extracting gas under the fire test with a suggested capacity of at least 2 x Vn where Vn is the
required capacity calculated by multiplying the air speed (2 m/s) by the height and width of the duct, e.g.
for the rectangular duct described in 6.1.3 with cross section of 1 m x 0,25 m:
3
Vn = 2 m/s x 1,0 m x 0,25 m = 0,5 m /s
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The characteristic curves of the fan shall be horizontal for the actual air flow. The conveyed air volume
flow of the fan shall not change by more than 10 % in the event of a drop in the pressure of up to 50 Pa.
4.9 Thermocouples
Sheathed thermocouples shall be provided for measuring the gas temperature adjacent to the nozzles of
nickel chromium/nickel aluminium type K wire as defined in EN 60584-1, with a nominal diameter of
1,5 mm to 3 mm. The thermocouples shall measure with an accuracy of ± 15 K. The position is shown in
Figures 6 and 7, item 6.
4.10 Surface thermocouples
Surface thermocouples for measuring surface temperature of the type specified in EN 1363-1 and at the
locations specified in EN 1366-1 shall be used.
4.11 Oxygen measuring equipment
The oxygen concentration at points G1 and G2 shall be measured using two separate systems consisting
of O analysers based on the paramagnetic measurement method and suitable equipment for cooling,
2
filtering and drying the gases. Appropriate connecting tubes and probes shall be provided. The 90 %
response time of the complete system shall be 20 s maximum. The accuracy shall be equal to or better
than ± 0,1 Vol-%.
4.12 Oxygen measurement probes
Gas probes made of stainless steel shall be provided for extracting the furnace gas from the inside of the
duct at the locations G1 and G2 in Figure 6. The end of the probe shall be located in the centre point of the
duct cross section.
An alternative gas probe according to Figure 14 can be used.
Both types of gas probes are described in 9.3.
4.13 Restraining equipment
Restraining equipment shall be applied as for duct B in EN 1366-1.
4.14 Deflection measurements
Deflection measurements shall be taken for determining the reduction of internal cross-section area at
ambient temperature and during the fire test. The measurement shall be done with an accuracy of ± 1mm.
The interval between a complete set of measurements shall not exceed 15 min, in any case near prior to
any classification time period.
5 Test conditions
The heating conditions and the furnace atmosphere shall conform to those given in EN 1363-1.
The furnace pressure shall be controlled to Δp = 15 Pa throughout the test at the mid-height position of
the horizontal ducts. For vertical ducts the furnace pressure shall be controlled to Δp = 20 Pa at a distance
of 100 mm below the ceiling. The tolerance of the pressure differential is given in EN 1363-1.
Details of test conditions within the ducts during the test are given in Clause 11.
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6 Test specimen
6.1 Size
6.1.1 General
For duct specimens of sizes other than those given in Table 3, the field of direct application is restricted
(see Clause 13).
6.1.2 Length
The minimum lengths of the parts of the test specimen inside and outside the furnace shall be as given in
Table 2 (see also Figures 3 and 9).
Table 2 — Minimum length of test specimen
Orientation Minimum length (m)
Inside furnace Outside furnace
Horizontal 3,0 4,2
Vertical 2,0 4,25
6.1.3 Cross-section
The standard sizes of ducts given in Table 3 shall be tested unless only smaller cross-sections are used:
Table 3 — Internal cross-section of test specimen (dimension of the open cross-section)
Rectangular Circular
Width (mm) Height (mm) Diameter (mm)
1 000 ± 10 250 ± 10 560 ± 10
6.2 Number
A minimum of one test specimen shall be tested. For horizontal and vertical installation, see 13.2.
6.3 Design
6.3.1 General
The test shall be made on a test specimen representative of the complete duct assembly, including
integral or intended insulation on which information is required. Each type of duct requires a different
approach and the laboratory shall as far as practical reproduce the edge conditions and the method of
fixing or support inside and outside the furnace to that representative of that used in practice. The
distance between the suspension devices and the distance between suspension devices and the
separating element shall be representative of the intended application as they are an integral part of the
tested system. It should be as far as is reasonably practicable the same arrangement as (or within DIAP
and/or EXAP rules) complimentary to the system tested in EN 1366-1 for the same duct.
6.3.2 Openings in duct
Two openings equal in size shall be provided, one on each vertical side of the duct inside the furnace. For
horizontal ducts the openings shall be positioned (500 ± 25) mm from the end of the duct inside the
furnace (see Figure 1). For vertical ducts the openings shall be positioned (200 ± 10) mm below the
furnace roof (see Figure 2).
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In both vertical and horizontal ducts, clear openings shall have the same width/height ratio as the cross-
section of the duct. For circular ducts, the openings shall be rectangular with a width/height ration of 4:1.
The total area of the openings shall be 50 % ± 10 % of the internal cross-sectional area of the duct.
Framing of the openings shall be as in practise (to avoid weakening the duct walls in the area around the
openings).
6.3.3 Joints in horizontal ducts
The test configuration shall include at least one joint inside the furnace and at least one joint outside it.
There shall be at least one joint in every layer of fire protection material (if applicable), both inside and
outside the furnace and in any steel duct.
Outside the furnace, the joint in the outer layer of the fire protection material shall be no further than
700 mm from the supporting construction and no nearer than 100 mm to thermocouples T2. Inside the
furnace, the joint in the outer layer of fire protection material shall be located at approximately mid-span.
The distance between joints and suspension devices shall not be less than that used in practice. If the
minimum distance has not been specified, suspension devices shall be arranged so that the joint of the
outermost layer at the bottom of the insulation material (if no insulation material is present: joint of the
steel duct) lies midway between them. Centres of the suspension devices shall be specified by the
manufacturer and shall be representative of practice.
6.3.4 Joints in vertical ducts
The test configuration shall include at least one joint inside and one joint outside it.
There shall be at least one joint for every layer of fire protection material, both inside and outside the
furnace and in any steel duct.
Outside the furnace, the joint in the outer layer of the fire protection material shall be no further than
700 mm from the supporting construction and no nearer than 100 mm to thermocouples T2. Inside the
furnace, the joint in the outer layer of fire protection material shall be located at approximately mid-span.
6.3.5 Support for vertical ducts
Vertical ducts shall be supported on the furnace floor and penetrate through the supporting construction
(see Figure 2); the ducts shall be fixed at the level of the supporting construction as they would be fixed
in practice when penetrating a floor. This shall be as specified by the sponsor.
6.3.6 Compensators
Where compensators are used in practice then they shall be incorporated in the test specimen. In this
case the compensator shall be located outside the furnace approximately 500 mm from the perforated
plate.
6.3.7 Access panels
Where access panels are used in practice then they shall be incorporated in the test specimen. In this case
the access panels shall be located outside the furnace approximately 500 mm downstream from the
perforated plate. In cases where compensator and access panel are included in one test specimen, the
placement of the compensator takes precedence (access panel shall be located (300 ± 50) mm from the
end of the compensator or in the next section downstream).
In cases where access panel are included in the test specimen causing conflicts with the joints in the
different layer
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